Palynology
study of plant pollen, spores and certain microscopic plankton organisms (collectively termed palynomorphs) in both living and fossil form / From Wikipedia, the free encyclopedia
Palynology is the study of very small natural particles. The word literally means the "study of dust". A palynologist is someone whose job is to identify what the particles are. Samples of particles can come from the air or water or soil or rocks. They could be organic and inorganic. Micropaleontology is a related area of study; it involves very small fossils.